Implement "Save image as" for canvas (chromium side).

content/renderer/render_view_impl.cc

Index: content/renderer/render_view_impl.cc
diff --git a/content/renderer/render_view_impl.cc b/content/renderer/render_view_impl.cc
index e66d313516fc459028f61da83cb9b3cf9212fe5c..7d96629325fbf9583b973f1626cd105ba01dba3f 100644
--- a/content/renderer/render_view_impl.cc
+++ b/content/renderer/render_view_impl.cc
@@ -1098,6 +1098,7 @@ bool RenderViewImpl::OnMessageReceived(const IPC::Message& message) {
     IPC_MESSAGE_HANDLER(ViewMsg_Stop, OnStop)
     IPC_MESSAGE_HANDLER(ViewMsg_SetName, OnSetName)
     IPC_MESSAGE_HANDLER(ViewMsg_CopyImageAt, OnCopyImageAt)
+    IPC_MESSAGE_HANDLER(ViewMsg_SaveImageAt, OnSaveImageAt)
     IPC_MESSAGE_HANDLER(ViewMsg_Find, OnFind)
     IPC_MESSAGE_HANDLER(ViewMsg_StopFinding, OnStopFinding)
     IPC_MESSAGE_HANDLER(ViewMsg_Zoom, OnZoom)
@@ -1243,6 +1244,10 @@ void RenderViewImpl::OnCopyImageAt(int x, int y) {
   webview()->copyImageAt(WebPoint(x, y));
 }
 
+void RenderViewImpl::OnSaveImageAt(int x, int y) {
+  webview()->saveImageAt(WebPoint(x, y));
+}
+
 void RenderViewImpl::OnUpdateTargetURLAck() {
   // Check if there is a targeturl waiting to be sent.
   if (target_url_status_ == TARGET_PENDING) {